diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index f780e223b118..239c9548b156 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -1002,9 +1002,15 @@ xfs_file_iomap_begin(
 		 * I/O, which must be block aligned, we need to report the
 		 * newly allocated address.  If the data fork has a hole, copy
 		 * the COW fork mapping to avoid allocating to the data fork.
+		 *
+		 * Otherwise, ensure that the imap range does not extend past
+		 * the range allocated/found in cmap.
 		 */
 		if (directio || imap.br_startblock == HOLESTARTBLOCK)
 			imap = cmap;
+		else
+			xfs_trim_extent(&imap, cmap.br_startoff,
+					cmap.br_blockcount);
 
 		end_fsb = imap.br_startoff + imap.br_blockcount;
 		length = XFS_FSB_TO_B(mp, end_fsb) - offset;